Cooler for firearms.



M. L. JOHNSTON.

COOLER FOR FIREARMS.

APPLICATION FILED JAN. 8. 191a.

Patented Mar. 4,1919.

lflk/ INVENTOR MLLLARII 4.. Jzw/vsm/v ATTOR N EY mm]: L. JOHNSTON, OFUTICA, NEW YORK.

COOLER FOB FIREARMS.

Specification of Letters Patent.

Patented Mar. 4, 1919.

Application fled January 8, 1918. Serial No. 70,892.

To all whom it may concern:

Be it known that I, MILLARD L. JOHNSTON, a citizen of the United States,residing at Utica, in the county of Oneida and State of New York, haveinvented certain new and useful Improvements in Coolers for Firearms, ofwhich'the following is a specification, reference being had therein tothe accompanying drawing.

My invention relates to a cooler for firearms, and I declare thefollowing to be a full, concise, and exact description thereofsufficient to enable anyone skilled in the art to which it appertains tomake and use the same reference being had to the accompanying drawingsin which like reference characters refer to like parts throughout thespecification.

The object of the invention is to rovide a simple, eficient device forcooling t e barrel of any gun when the same is being fired especially ina rapid manner. The invention will be found particularly useful inconnection with automatic reloading firearms and machine guns.

This object will be understood by referrin to the drawings in which:

igure 1 is a central longitudinal sectional view of the cooler and ofthe barrel of a firearm to which it is attached;

Fig. 2 is a central longitudinal section of a modified form of thecooler assembled to i the muzzle end of a barrel of a firearm;

end.

Fig. 3 is a perspective view of a front sight employed.

Fi 4 is a fragmentary view in section of a stil further modified form ofthe cooler.

Referring more particularly to the drawings, the barrel of an ordinaryfirearm is represented by 1 and is provided with the chamber 2 for thereception of the cartridge 3 and the duct 4 of any given caliber for theprojection of the bullet 5. The duct or channel 4 has the usual spiralgrooves with a certain number of turns, whereby to efiect a rotation ofthe bullet 5 in its projection,and also the channel 6 of larger diameterthan the channel 4, adjacent its muzzle The channel 6 is provided withthe ports 7 whose walls are disposed on an incline toward the rear ofthe barrel --1-, in order to furnish a lead for the air that is suckedthrough the said ports 7 in the wake of the bullet 5 and the propellinggases. The ports 7 are as numerous as desired to effect a given draft ofair therethrough, that will be sufiicient to cool the barrel 1- of thegun. The ports 7 lead or open into the chamber 8 that surrounds thebarrel 1-.

The chamber 8 is slightly larger adjacent the rear end of the barrel 1than it is adjacent the front or muzzle end, and is inclosed 'by thecasing 9 having the end members 10 and 11 provided with suitableorifices for the reception of the respective portions of the barrel '1-.The casin 9 is held in assembled position upon the arrel 1 by the setscrews 12 that are threaded in the apertures in the end members 10 and11. Furthermore, the casing 9 has a plurality of ports 13 giving accessto the outer air. The ports 13 are abundantly numerous to admit of asufiicient quantity of air for circulation through the chamber 8.

The operation of the invention is effected, whereby to cool the barrel1, when the gun isbeing fired, by causing a circulation or draft of airalong the outer surface of the barrel 1- in the direction, as indicatedby the arrows in Fig. 1. This draft is secured automatically by means ofthe suction that follows in the wake of the bullet 5 and of theonrushing or propelling gases.

The cartridge 3 having been discharged, the bullet 5 will be forcedthrough the channel 4 by the expanding gases. Immediately,

however, the bullet 5 reaches the larger channel 6, the gases will bereleased and rush forward and out through the muzzle of the gun. Theresult of this momentum of the gases and the projected bullet will causea suction of air or draft throu h the ports 13, the chamber 8,, theports 7, t e channel 6 to the outer air, and thereby keep the barrel 1-of the gun cool, so that the gun can be fired rapidly for comparativelylong periods of time without becoming overheated.

Fig. 2 shows a modification embodying a member 20, which may be held tothe muzzle end of the barrel 21 by the set screws 22. The member 20 hasa channel 23 that'is in alinement with the bore 24 of the barrel 21,although somewhat larger in diameter, so as to release the expandinggases in the rear of the char e. The four branch channels 25 are providebeing open to the outer air as at 26 and communicating with the channel23, adjacent or just in advance of the end of the muzzle of the barrel21, at 27.

In operation, the charge, when exploded of the usual 01 customary frontand rear sights in one. This sight is employed in con-. nection with arear sight of well known construction.

Fig. 4 shows a still further modification in which the forward enlargedchannel 6 of the barrel 1 is provided with the channels 30 that aredisposed in opposite position to the corresponding ports 7 of Fig. 1,and communicate with the channels 31 formed in the forward end of thecasing 9. The channels 31 communicate with the interior of the casing 9or with chamber 8 and with the open air.

By this arrangement of the channels 30 and 31, the suction of air alongthe barrel 1 is effected both before and after the passage of the chargefrom the barrel of the rearm. Before, because of the pressure of air inadvance of the bullet 5, and after because of the suction'that followsin the wake of the charge.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1, In a cooler for firearms, a casing, a

barrel, and ports in said barrel alining with ports in sa d casing,whereby to permit a draft of air both before and after the charge tochill the barrel of the firearm.

2. In a cooler for firearms, a barrel having a channel for theprojection of a bullet, a

larger channel communicating with said first named channel, a casingsurrounding channels in said barrel, whereby a suction of air along saidbarrel is effected both before and after the passage of the charge, tocool said firearm.

4. In a cooler for fireams, a barrel havinga channel for the projectionof a bullet, a casing surrounding said barrel, channels formed on anincline in said barrel, other channels formed in said casing and adaptedto aline with said channels in said barrel, and means whereby to cause asuction of the air along the barrel both before and after the passage ofthe charge, whereby to cool the firearm.

5. In a cooler for firearms, a barrel having a channel for theprojection of a bullet, a larger channel communicating with said firstnamed channel, a casing surrounding said barrel, channels formed on anincline in said barrel, other channels formed in said casing on anincline to aline with the channels in said barrel, and still otherchannels formed in said casing to communicate with the air,'whereby thepassage of the bullet along the channel in the barrel will cause asuction of air along the barrel, both before and after the passage ofsaid bullet, to cool said firearm.

In testimony whereof I have afixed my signature. e

MILLARD L. JOHNSTON.

